10. Natural Resources and Environmental Sustainability


This book has focused on human systems, physical systems, and the relationship between them. One area where the interaction of human and physical systems is particularly evident is in our use of natural resources. Geographers are interested in studying natural resources because natural resources are spread unevenly over the Earth (some places have a lot of natural resources while others have few) and conflicts can occur over control of resources. We can also see that the use of one resource can destroy another. The big ideas from this chapter are:


  1. Natural resources are any Earth material that people find useful. 
  2. Natural resources have values based on their consumptive use, non-consumptive use, and even their being left alone for future generations or merely to exist.
  3. Conflicts may occur when the use of one resource destroys another. These conflicts can occur at different geographic scales.

1. Natural resources and sustainability

A natural resource is any Earth material or process that people find useful. A narrow definition of natural resources considers only those things that are economically productive, but such a definition misses a lot of resources that may be difficult to place dollar values on. For example, while we can think of mineral resources like gold or tungsten to be worth a certain amount of money, it's much harder to place a dollar value on a resource like clean air or clean water. 

Natural resources can be broadly divided into renewable and non-renewable resources. Renewable resources are replenished (or created) at a rate greater than or equal to their rate of use. For example, fresh water is considered a renewable resource because it is constantly being renewed through the process of evaporation from the world's oceans and precipitation.

Logging on the Olympic Peninsula. Forests represent a renewable resource if they are harvested at around the same rate they grow. However, the consumptive use of forests precludes other, non-consumptive uses, described below. Photo by Flickr user Sam Beebe, used under CC BY 2.0 license (https://www.flickr.com/photos/sbeebe/5225636134)

In contrast, non-renewable resources have a finite supply. Either they are not being replenished at all, or their rate of use is much greater than the rate at which they are created. Examples of non-renewable resources include common energy resources like uranium (not being replenished at all) or fossil fuels (being replenished at a much, much slower rate than they are being used).

Oil wells in North Dakota. Oil is a non-renewable natural resource because it is being consumed at a rate much, much faster than it is being produced--oil takes millions of years to form from organic material buried deep in the Earth, but reserves are forecast to be exhausted in hundreds of years at present rates of use. Photo by Flickr user Tim Evanson, used under CC BY-SA 2.0 license. (https://www.flickr.com/photos/23165290@N00/9287130523)

Considering whether resources are renewable or not introduces the concept of sustainability. Sustainability refers to our ability to use Earth's resources, including its natural systems, into the future beyond our lifetimes. While in the very long run life on Earth will be extinguished with the exhaustion of the Sun, we can still talk about what we would like our children, and their children, to inherit. In that context we can understand that some courses of action are less sustainable and others are more sustainable. This also avoids the false dichotomy of "sustainable" versus "unsustainable" discussions. 

2. Valuing natural resources

As already mentioned, natural resources may be difficult to value--but that doesn't make them valueless. Resources may have values that are high yet difficult to put in dollars-and-cents terms. All of the discussion in this section has more detailed explanations in microeconomic theory, but don't worry, we won't get bogged down in those specifics here.

First, consider a forest. When seeing the term "forest resources" people most often think of cutting down trees to create wood and paper products. The trees are used up and turned into consumer commodities. This value, the consumption use value of  trees, is easily estimated because the commodities are bought and sold. 

But a forest has values that may not come immediately to mind yet are every bit as real. Forests  left standing perform important ecological functions that benefit humans in multiple ways. For example, forests slow erosion, filter water and slow floodwater surges from precipitation; they produce oxygen and remove carbon dioxide from the air, and they moderate the local climate by adding humidity to the air and creating shade (just compare the temperature of a forested area to a busy city center on a hot summer day). All of these functions present a use value, but represent a non-consumptive use: using the forest for shade or flood prevention does not use it up like cutting it down for lumber would. While these uses are unquestionably valuable, they are harder to put a price on directly because their uses are not commonly bought or sold like lumber or paper. In the example of forests, these non-consumptive uses are often called ecosystem services because the forest continues to provide them as long as it remains intact. 

There are still other non-consumptive use values to the forest. For example, if someone enjoys hiking through the forest, the forest is providing these benefits without being used up. Many parks and preserves, including America's extensive national park network, represent these non-consumptive use values. People travel from around the world at great expense to see the Grand Canyon, Yellowstone, or Yosemite, yet they don't take any resources from these places--they pay park entry fees and travel expenses just for the experience of visiting the parks and looking at the sights inside them.

Backpackers on the Heliotrope Ridge Trail, Mount Baker, Washington, represent a non-consumptive use of forest resources. 2005 photo by Tim Scharks.

But there is another set of values for the forest, called non-use values or passive use values. These values are much harder to estimate yet most people would agree they exist. In the case of our forest, we can agree that having a forest is valuable because of the potential to use it in the future. That is, we agree that a forest is a valuable thing because we might someday want to cut it down. This is called the option value of the natural resource: We would be willing to pay something now to have the option to use a resource later. 

Another non-use value in similar lines is bequest value, which is the value we place on leaving a resource for future generations. We might not benefit directly from the resource ourselves, like a remote mountain range in Alaska, but we might enjoy knowing that it will be preserved for future generations to use or preserve as they choose. 

Finally, economists have a term for the value of knowing that something simply exists, appropriately enough called existence value. This value is one of the more difficult to estimate because it does not depend on current or future generations using or even thinking of using a resource. Existence value is most often applied to animal species threatened by extinction. Take the example of the blue whale: these whales can be seen through whale tourism but are much less common and less easily viewed than other species like the grey whale, so most people in the world are not likely ever to see a blue whale. Yet if asked, many people would say that they would feel a sense of loss if they learned the blue whale was extinct. Importantly for economic valuation, many of those people might also be willing to pay a slightly higher price for seafood if they knew it contributed directly to the survival of the blue whale. This existence value may be less tangible than some other values but economists agree that it's important to consider. 

It's possible to catch a glimpse of the blue whale, the largest animal on Earth, on whale watching tours. But most people in the world will probably never see one and never plan to see one, yet would feel a sense of loss if they learned the species had become extinct. Photo by Flickr user Aprille Lipton, used under CC BY-SA 2.0 license.(https://www.flickr.com/photos/24891611@N03/9021186772)

3. Resource conflicts: conflicting uses and pollution

The previous discussion should make it clear that sometimes consumptive uses preclude non-consumptive uses: hikers don't generally enjoy walking through clear cuts. Let's look at another, more dramatic example of when the use of a resource destroyed another use for that same resource. 

The Aral sea is a body of salt water in Kazakhstan and Uzbekistan. The sea had been at equilibrium, with the water flowing in from two rivers matched by evaporation from the sea. The sea had a productive fishery, producing a renewable harvest of up to 40,000 metric tons of fish per year. 

But some people had other plans for the water that kept the Aral Sea full. Under the Soviet Union and thereafter, the rivers were diverted for irrigation of food crops and cash crops, especially cotton. The water was a valuable resource for this agricultural productivity, but it came at a cost-diverting the water from the river and into fields increased its evaporation so less and less could reach the Aral Sea. The result was very predictable in hindsight: 

Animation of the shrinking Aral Sea, 1984-2012, by Google Earth Engine (https://earthengine.google.org), using Landsat satellite imagery.

The Aral Sea fishery was destroyed, leaving ghost towns in the middle of desert. The trade-off between resource uses has not been entirely equal, either, as the farmlands have been less productive than planned as salt builds up from rapid evaporation in the dry climate. Planners are attempting to restore the North Aral Sea, a small sub-basin of the formerly vast sea, to a productive fishery, but progress has been limited.

The Aral Sea example is a resource trade-off, where one use of the resource was substituted for another. Sometimes the use of a resource can damage or destroy another resource. When a byproduct of resource use is harmful to people or the environment, it is called pollution. The consumption of many natural resources may result in pollution: one example is the pollution of air by the use of fossil fuels (gasoline, diesel, natural gas, and coal).

Fossil fuels are an important energy resource for heating (natural gas), electricity generation (coal), and transportation (gasoline and diesel). But burning fossil fuels results in three different scales of air pollution.

At the global scale, the byproducts of burning fossil fuels results in two different, related environmental impacts from the creation of higher levels of carbon dioxide: global climate change (covered in detail in Chapter 3) and ocean acidification. Ocean acidification is caused by higher levels of carbon dioxide dissolving in the world's oceans, changing its pH and harming corals and other aquatic life.

At the regional scale, burning coal results in acid precipitation, commonly called acid rain. Acid rain at low concentrations can damage aquatic ecosystems, especially young fish, and at higher concentrations can even kill forests.

At the local scale, when environmental conditions allow for the buildup of tailpipe emissions from cars and other vehicles, smog can form in urban areas. Smog is not good for plants or animals but since it occurs in cities it's mostly bad for human health, especially affecting the elderly and other people with issues like asthma. Smog and acid rain together may also degrade cultural resources such as the edifices of old buildings, important monuments, and even headstones on graves.

Smog over downtown Mexico City. Photo by Flickr user Tjeerd Wiersma, used under CC BY 2.0 license (https://www.flickr.com/photos/tjeerd/2809358).